I did this by ear so it may not be 100% accurate. It's pretty simple strumming and easy to follow if you listen 
to the song. I noticed there wasn't chords for this and I love this song so I needed to share :) 

                G 
If I were the ocean, 
              C 
I could pull back for you 
      D          G 
And I could fill up for you; 
               D G     G 
Cause you are the moon 


(Em)        G 
And I am but the sea, 
           C 
The wide blue, 
            D  G     G 
Staring up at you 

Am           C 
Ooooh, 
C            G 
You're my moon,  
C  G     C  G      G 
My moon, my moon 

D    G                         D    C          G 
They don't know why I love you like I do 
G                        C                          C 
And gravity don't have a thing to do with you or me 

C   G    G D   C     G   D 
My moon, you're my moon,  
G  C      G               D           G 
You're my moon 

Em    D         Em                D 
I made a tidal wave just to get close to you 
Em    D         Em                D 
I made a tidal wave just to get close to you 
Em    D         Em                D 
I made a tidal wave just to get close to you 

C      G 
My moon,  
C            G     D 
You're my moon,  
C     G      D 
My moon 

(stop strum)    
            
         (start)G 
If I were the ocean, 
G               C           D 
I could pull back for you 
D           Gm      D G 
I could fill up for you, 
       D       Am  C 
Cause you are the moon  

<3<3<3